Means controlling the extent of mechanical movements in printers, linecomposing machines and other machinery



Feb. 14, 1961 e DIRKS MEANS CONTROLLING THE EX'I ENT OF MECHANICAL MOVEMENTS IN PRINTERS, LINE-COMPOSING MACHINES AND OTHER MACHINERY Filed Aug. 26, 1957 Fig. 1

INVENTOR Maw RTTORNE-H United States Patent MEANS CONTROLLING THE EXTENT OF ME CHANICAL MOVEMENTS IN PRINTERS, LINE- COMPOSING MACHINES AND OTHER MA- CHINERY Gerhard Dirks, 44 Morfelder Landstrasse, Frankfurt am Main, Germany The present invention relates to a means for controlling the extent of a mechanical movement in dependence on avalue represented by a train of pulses, One use of the invention is in the justification of lines of text in a reproduction device such as a photo-composing machine, typewriter, or the like in which there is a relative move ment in the line direction between a reproduction unit and an image receiver. The invention wil be described mainly as adapted for this particular use.

It is an object of the present invention to provide means for adjusting the rate of relative movement between the reproduction unit and the image receiver, in dependence on the extent of justification necessary in each line.

In one arrangement, where the said relative movement is a stepwise movement, the drive means which effects the said relative movement includes a magnetic clutch and brake device having driving and braking windings, and there are thyratron or similar electronic means controlling each, with switch-over means between them so that they operate alternately, and also a counting stage for actuating said electronic means. When a starting pulse is applied to start the operation of the counter, the said relative movement begins at the same time between the reproduction unit and the image receiver and such movement produces other pulses which are fed to the counter. It is to be assumed that the character to be reproduced has previously been recorded in a storage device and when this device is sensed for reproduction it feeds to the counter a number of pulses corresponding to the width of the character. The subsequent movement of the reproduction unit (or image receiver) causes likewise the injection of pulses and thus operates in a conventional manner the counter additively or subtractively and when zero or maximum is reached actuation is switched over from one to the other thyratron, the drive thereby being stopped and the brake applied. Printing or other image forming may then take place within the letter-space whose width has been determined by the counter.

There may be put into a space command counter a control for the various spaces and this may be done by separate input means delivering a number of pulses respectively corresponding to a normal minimum space width and to a justfication width, or from a single input means delivering a number of pulses corresponding to the ascertained total space width.

For all letters and spaces between them the extent of the said relative movement may be controlled from two sources feeding into a command counter, one source being in dependence on the normal letter width and the 2,971,623 Patented Feb. 14, 1961 other in dependence on the ascertained justification width. Alternatively, there could be a differential mechanism in the drive for said relative movement which may receive one entry in dependence on the normal letter width and another in dependence on the justification width for example through a magnetic clutch device controlled by counters as described above.

In cases where there is a constant speed drive for the said relative movement between reproduction unit and image receiver, there may for example be an outside motion generator, which may have a variable output, and this will be under the control of a command counter determining how many justification units of width are to be included in the movement for the respective letter spaces.

In such a case the first pulse after the sensing of the character signals in the the storage device actuates a clutch in the drive means and also starts the counter. The pulses are counted to zero (or maximum) and at the end of the count the said relative movement is interrupted by a pulse generated by the counter. The extent of the movement therefore depends on the number and frequency of the pulses. With the number of pulses dependent on the normal character or spacing width, the frequency of the pulses, if reduced, will cause the constant speed drive to produce a movement corresponding to the additional length required for justification.

The variation of the step length for justification purposes may be obtained by the use of a variable frequency generator, with, for example, variable resistance and capacitance components. Alternatively, a variation may be effected by the sensing of signals of different kinds or frequencies in different signal tracks in said storage. An additional method of variation is by varying a resistance in the motor circuit.

In those cases where a variable speed drive is used, there may be clutches in the drive operating at diilerent time instants, and either the said speed or the said time instants may be dependent on the normal character widths and correspondingly the time instants or the speed will be varied according to the additional widths to be added for justification. The time period in the former alternative may be governed by a constant frequency generator.

For each space that is stored in the storage a signal must be given (and recorded) indicating what variation of speed or time is to be made, and eitecting that variation.

in order that the present invention may be readily carried into effect; it will now be described with reference to the accompanying drawing, wherein:

Fig. 1 is a schematic circuit diagram of an embodiment of a device for controlling a movement in de pendence on pulse values;

Fig. 2 is a schematic diagram of an arrangement utilizing two of the devices of Fig. l; and

Fig. 3 is a schematic circuit diagram of a modification of the embodiment of Fig. 1.

Fig. l is an arrangement for controlling the rotation of a shaft 1 in dependence upon a train of pulses. Since, however, it is possible to convert this rotation into any other form of movement, it is possible to control such other forms of movement with the same control means. The arrangement includes the motor 2, which through shaft 3 drives a magnetic clutch and brake device 4 which in turn drives the shaft 5 connected to shaft 1.

energizing the brake-winding.

' vents any rapid change in the anode voltage.

lacunae A pulse-generator 6 is mounted on shaft and delivers pulses through lead 7 to the counting-stage 3 in synchronism with the rotation of shaft 5. That is, the number of pulses delivered is proportional to the degree of rotation of shafts 5 and it. The generator 6 preferably consists of a toothed magnetic disc attached to the shaft, with an associated pick-up system arranged in the manner described on pages 357-360 of the Journal of Scientific Instruments, October 1954. Magnetic device 4- includes both brakingand driving-windings. The drivingwinding is controlled by the cold-cathode thyratron 9 and the brake-winding is controlled by the cold-cathode thyratron iii. A clutch-and-brake device is described for instance in Patent No. 2,672,067.

The arrangement operates as follows:

In the initial condition the cold-cathode thyratron 10 is in ignited condition and therefore the brake-winding of the magnet device 4 is energized while thyratron 9 is extinguished and the driving winding is deenergized. Therefore, shaft 5 is held at rest whereas shaft 3 rotates, since it is driven continuously by motor 2.

If pulses from a controlor storage-device are delivered through lead 11 to input-lead 12 of the counting stage 8, for example a number of pulses indicating the widths of the characters in a line being set up in a line composing machine (and therefore indicating the corresponding required degree of movement of shaft ll), then this train of pulses will advance the counter additively to a certain value and will also be delivered through lead 13 to the igniting electrode of cold-cathode thyratron 9. Thyratron 59 will thereby be ignited, energizing the driving winding of magnet-clutch 4, whereas cold-cathode thyratron It) will be extinguished, thus automatically de- The automatic extinction of cold-cathode thyratron 10 is produced because the anode voltage is effectively stabilized by capacitor 14 but the cathode voltage increases since the current through the common cathode resistor 15 is increased by the igniting of both cold-cathode thyratrons 9 and 10, and therefore the voltage across thyratron ltl falls below the glow voltage.

Consider the stable condition of the conducting tube. With a supply voltage of one hundred volts, there might be forty volts dropped across the resistance winding in the anode circuit, twenty volts dropped across the tube itself, and the remaining forty volts dropped across the common cathode resistor. This is the normal condition of'the conducting tube with a maintaining voltage across it of twenty volts. When the non-conducting tube is fired by an input signal, it also draws current through the common cathode resistor, so that the voltage across the cathode resistor rises instantaneously to approximately fifty-five volts. The capacitor between the negative supply line and the anode of the conducting tube pre- Thus the tube which was originally conducting has the voltage across it instantaneously reduced approximately five volts. This voltage is insufficient to maintain the discharge and the tube is deionized. The previously nonconducting tube then assumes the stable conducting condition described above.

The energizing of the driving-winding of the magnet device 4 transmits the drive to the shaft 5, the pulse generator 6 and the shaft 1. Pulses will then be delivered from pulse generator 6 through lead 7 to counting stage- 8 in synchronism with the rotation of shaft 1 operating the counting stage 8 subtractively so as to return it to its initial position from the position caused by the injection of a certain number of pulses through lead 11. When this initial position is reached, a pulse is generated on lead 16 which again ignites cold-cathode thyratron ft and also extinguishes cold-cathode thyratron 1. The driving winding of the magnet device 4 will thereby be deenergized and the brake-winding will be energized, so

that the rotation of shafts 5 and 1 is stopped. Further pulses may be delivered by lead 17 to the counting-stage 8 operating it additively and these pulses will also go to lead 13 to repeat the cycle. If the arrangement is used in connection with a line composing machine, the pulses delivered to counting stage 8 by lead it may for ex ample control the normal movement of the machine for effecting a space between two words and the pulses delivered to counting stage 8 on lead 17 may control the additional movement for justification of the line by causing a greater number of steps. More revolutions of shafts 5 and 1 will be required in such case for returning the counter to its initial position.

A combination of these two movements may also be effected by the arrangement of Fig. 2. In Fig. 2 two control-devices 18 and 19, each corresponding to the arrangement of Fig. 1, are utilized. Pulses will be delivered to control device 18 through lead 11 for example controlling the said normal movement, whereas pulses will be delivered to control device 19 through lead 17 controlling the said additional movement. The move ments of the two shafts 1 will be combined in the differential-gear 20 thereby effecting the required degree of movement of shaft 21 which is the one to be controlled.

Another possibility for controlling a movement in de pendence on two values is to vary the number or fre-- quency of the pulses operating the counting stage subtractively. Such an embodiment is shown in Fig. 3. This arrangement includes motor 22, driving shaft 23, magnet device 24- and the shaft 25. Magnet device 24 includes a brake-winding and a driving-winding. The brake-winding is controlled by cold-cathode thyratron 26 and the driving-winding by cold-cathode thyratron 27.

To control the rotation of shaft 25 first pulses will be delivered e.g. from said storage device to pulse-generator 28 through lead 29 for determining the frequency of the pulses to be delivered from this pulse-generatoriu accordance with a necessary increased or reduced movement of shaft 25, for example for the purpose of justification in line composing machines. Then a number of other pulses will be delivered e.g. from said storage device to input-lead 31 of counting stage 32 through lead 30 advancing this counting stage additively. These other pulses are representative of the necessary normal movement of a shaft 25, for example a movement corresponding to a normal space step in a line of a line composing machine. The counting stage 32 and the counting stage 8 are preferably multi-cathode gas discharge tubes, the operation of which is fully described in the article entitled The Dekatron by Bacon and Pollard, published in Electronic Engineering, dated May 1950.

Subsequently, these other pulses will be delivered from lead 30 through lead 33 to pulse-generator 28 starting the delivery of a series of pulses through lead 34 to counting stage 32 at the set frequency. These latter pulses delivered from pulse-generator 28 will operate the counting stage 32 subtractively to return it to its initial position from the position reached by the injection of said number of other pulses. Also said other pulses from lead 39 will be delivered through lead 35 to the igniting electrode of cold-cathode thyratron 27 igniting it. Cold-cathode thyratron 26 will thereby be extinguished as explained in reference to Fig. 1 and therefore the brake-winding of magnet device 24 will be deenergized and its driving-winding will be energized.

In this way, the shaft 25 is rotated at constant speed simultaneously with the delivery of pulses through lead 34 to counting stage 32. After counting stage 32 is returned to its initial position by pulses delivered to lead 34 a pulse available at lead 36 is delivered through lead 37 to pulse generator 28 stopping the delivery of further pulses from this pulse generator to counting stage 32. Simultaneously, the pulse in lead 36 is delivered through lead 38 to the igniting electrode of cold-cathode thyratron 26 igniting it and extinguishing cold-cathode is then energized and the driving-winding is deenergized, so that the rotation of shaft 25 is stopped.

Because the frequency of pulse-generator 28 was determined initially by the first pulses delivered to it by lead 29 and because furthermore by pulses in lead 30 a predetermined number of pulses was caused to be delivered through lead 31 to counting stage 32, until it was returned by pulses through lead 34 to its initial position, the extent of movement of shaft 25, which is controlled by both said groups of signals, is also determined.

Although the arrangement of the present invention is mainly described in connection with a line composing machine, it is obvious that all other forms of movement may be controlled in the same way.

WhatI claim is:

1. Apparatus for controlling the extent of a mechanical movement in dependence on a value represented by a train of pulses, comprising, in combination, a constantly rotating driving shaft; a driven shaft the extent of movement of which is to be controlled; electronic switch means with first and second stable states adapted to be switched in response to signals applied thereto; a coupling device operable by electrical potentials derived from said electronic switch means and capable of coupling said driving and driven shafts together when said switch means is in its first stable state and capable of decoupling said shafts and of holding said driven shaft stationary when said switch means is in its second stable state; an electronic counter having first and second inputs and being responsive to pulses applied thereto so as to add and subtract respectively, and to generate a signal upon registration of a predetermined value; a variable frequency pulse generating device; means for applying a signal to said pulse generating device to predetermine its pulse frequency; means for applying a train of pulses to said pulse generating device to render it operative so as to apply pulses to one input of said counter at the set frequency; means for applying said train of pulses to the other input of said counter; means for applying said train of pulses to said electronic switch means to switch it to its first stable state; and means, operative in response to the registration of a predetermined value by said counter, for applying a signal to said electronic switch means to switch it to its second stable state and to said pulse generating device to render it inoperative.

2. Apparatus for controlling the extent of a mechanical movement in dependence on a value represented by a train of pulses, comprising, in combination, a constantly rotating driving shaft; a driven shaft the extent of movement of which is to be controlled; electronic switch means comprising a first and a second cold-cathode thyratron tube interconnected with each other for pushpull operation and with first and second stable states adapted to be ignited alternatively in response to signals applied thereto; a coupling device operable by electrical potentials derived from said electronic switch means and capable of coupling said driving and driven shafts together when said switch means is in its first stable state with only said first thyratron tube being ignited and capable of decoupling said shafts and of holding said driven shaft stationary when said switch means is in its second stable state with only said second thyratron tube being ignited; an electric counter having first and second inputs and being responsive to pulses applied thereto so as to add and subtract respectively, and to generate a signal upon registration of a predetermined value; a variable frequency pulse generating device; means for applying a signal to said pulse generating device to predetermine its pulse frequency; means for applying a train of pulses to said pulse generating device to render it operative so as to apply pulses to one input of said counter at the set frequency; means for applying said train of pulses to the other input of said counter; means for applying said train of pulses to said electronic switch means to switch it to its first stable state; and means, operative in response to the registration of a predetermined value by said counter, for applying a signal to said electronic switch means to switch it to its second stable state and to said pulse generating device to render it inoperative.

3. Apparatus for controlling the extent of a mechanical movement in dependence on a value represented by a train of pulses, comprising, in combination, a constantly rotating driving shaft; a driven shaft the extent of movement of which is to be controlled; electronic switch means comprising a first and a second cold-cathode thyratron tube interconnected with each other for push-pull operation and with first and second stable states adapted to be ignited alternatively in response to signals applied thereto; an electromagnetic coupling device having a driving winding and a braking winding operable by electrical potentials derived from said electronic switch means, said driving winding being connected with said first thyratron tube and capable of coupling said driving and driven shafts together when said switch means is in its first stable state with only said first thyratron tube being ignited, said braking winding being connected with said second thyratron tube and capable of holding said driven shaft stationary when said switch means is in its second stable state with only said second thyratron tube being ignited and said shafts being decoupled due to said first thyratron tube being extinguished; an electric counter having first and second inputs and being responsive to pulses applied thereto so as to add and subtract respectively, and to generate a signal upon registration of a predetermined value; a variable frequency pulse generating device; means for applying a signal to said pulse generating device to predetermine its pulse frequency; means for applying a train of pulses to said pulse generating device to render it operative so as to apply pulses to one input of said counter at the set frequency; means for applying said train of pulses to the other input of said counter; means for applying said train of pulses to said electronic switch means to switch it to its first stable state; and means, operative in response to the registration of a predetermined value of said counter, for applying a signal to said electronic switch means to switch it to its second stable state and to said pulse generating device to render its inoperative.

4. Apparatus for controlling the extent of a mechanical movement in dependence on a value represented by a train of pulses, comprising, in combination, a constantly rotating driving shaft; a driven shaft the extent of movement of which is to be controlled; electronic switch means comprising a first and a second cold-cathode thyratron tube interconnected with each other for push-pull operation and with first and second stable states adapted to be ignited alternatively in response to signals applied thereto; an electromagnetic coupling device having a driving winding and a braking winding operable by electrical potentials derived from said electronic switch means, said driving winding being connected with said first thyratron tube and capable of coupling said driving and driven shafts together when said switch means is in its first stable state with only said first thyratron tube being ignited, said braking winding being connected with said second thyratron tube and capable of holding said driven shaft stationary when said switch means is in its second stable state with only said second thyratron tube being ignited and said shafts being decoupled due to said first thyratron tube being extinguished; an electronic counter having first and second inputs and being responsive to pulses applied thereto so as to add and subtract respectively, and to generate a signal upon registration,

of a predetermined value; a variable frequency pulse generating devices; means for applying a signal to said pulse generating device to predetermined its pulse frequency; means for applying a train of pulses to said pulse generating device to render it operative so as to apply pulses to one input of said counter at the set freamaze fquency;means-forapplying said train of pulses to the other input of saidcounter; means for applying said train Lof pulses to said first thyratron tube for switching said electronicswitch means to its first stable state; and means, operative in response to the registration of a predeterwnined value bysaicl counter, for applying a signal to .said second thyratron tube for switching said electronic switch means to" its second stable state and to said pulse generating device to render it inoperative.

UNITED STATES PATENTS Logan ,May 22, Heising Jan.- 3.0, Sharple'rs et a1. Sept. 23, Hansell Mar. 16, Sampatacos et a1. Dec. 21,, Dimmer Oct. 16, Atton et al June 25, 

